Mr Hague -- a former DHB chief executive -- said a young person waiting weeks or months for help would experience worsening mental health problems.
"So we're looking at self-harm, we're looking at depression, we're looking at kind of starting to fail in school and I guess at the worst end of things it may be suicide that we're talking about."
If a young person didn't receive the health services they needed to thrive, it could also have lifelong consequences.
"By not meeting their needs now we are ensuring that we will have bigger problems for them to deal with and for our services to have to try and deal with later on in their lives."
Mr Hague said he wanted an urgent increase in mental health funding, a reinstatement of the Mental Health Commission and an urgent nationwide enquiry into mental health services.
He'd been hearing of more and more cases of things going disastrously wrong for individuals and the cases had "the hallmarks of a system in crisis", he said.
One DHB says its young people are getting help more quickly than before.
In the year to March, 32.6 per cent of those aged 19 and under seeking mental health help in Hawke's Bay waited more than three weeks to see a provider and 9.8 per cent more than eight weeks.
Hawke's Bay DHB service director mental health, Allison Stevenson, said the situation had improved since the March data was released.
She said 86.1 per cent of young people were now receiving mental health care within three weeks, which exceeded the national target of 80 per cent.
Hawke's Bay Mental Health Services had been transformed through a new model of care introduced from 2015.
"Much of the new model of care is focused on making it easier for everyone to access mental health services and we have moved a number of services out into the community and closer to people's homes."
The DHB had also opened a new $20 million mental health unit, Nga Rau Rakau, earlier this year, designed to meet the needs of all age groups with appropriate accommodation, treatment areas and rooms.
Ms Stevenson said there had been considerable work done to improve wait times for young people needing to access mental health services including ongoing recruitment and opening clinics in Napier, Wairoa and Central Hawke's Bay as well as from Hawke's Bay Hospital.
In Whanganui, where 35.6 per cent of young people waited more than three weeks for care, referrals are triaged.
Whanganui DHB clinical nurse manager Janice Bowers said all referrals were triaged and appointments made according to the level of risk.
Young people considered urgent were seen on the day of referral, semi-urgent referrals were seen within a week and regular referrals within three weeks where possible. If someone was not seen within three weeks, it was usually at their own request, said Ms Bowers.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
If it is an emergency and you feel like you or someone else is at risk, call 111.
